The present invention relates generally to roof-covering devices, and more particularly to a boot for covering and providing a water-tight seal around a protrusion on a roof.
Polymer coated membranes are commonly used to cover roofs. Often, the membrane is custom designed for the particular roof on which it is used. The roof measurements are provided to the factory which creates a unitary membrane from separate pieces which have been heat welded together.
Although these roofs are generally flat, there are frequently items protruding from the surface of the roof, such as vents, ductwork, air conditioning units, and the like. The size of these items should be provided to the factory so that accommodations can be made for them in the membrane. Locations of these items at certain points on the roof may also be provided to the factory.
The present invention specifically relates to a boot for covering and sealing a vertical protrusion (e.g., pipe) extending from a roof to be sealed. As discussed, when installing a roof membrane, it is desirable to provide a water-tight seal around protrusions in a roof. Typically, when installing a boot around a protruding pipe, generally three seals are made to provide a water-tight seal around the pipe:                1.) a base portion of the boot should be sealed to a top portion of the boot (e.g. hot air sealed, welded, glued, or caulked);        2.) the base portion should be sealed to the roof or a roof membrane that may be formed of the same or similar material as the base portion, or another material that may be heat bonded or otherwise sealed with the base portion in a leak proof manner (e.g. hot air sealed, welded, glued, or caulked); and        3.) a top end of the top portion of the boot should be sealed around the pipe to prevent water from entering any space between the boot and the pipe.        
Currently this process of sealing a protruding pipe takes a relatively long time and can result in a poor seal. Accordingly, the present invention relates to a new method and apparatus for sealing vertical protrusions on a roof allowing the boot of the present invention to be relatively easily installed and adjusted to provide a tight seal for protruding pipes.
The boot of the present invention may be preferably comprised of: a top portion adapted to surround a predetermined portion of the protrusion (e.g., pipe) to be covered, the top portion having a top end and a bottom end, wherein the top end has a top opening and wherein the bottom end has a bottom opening; a base portion, wherein the base portion may be connected to a bottom edge of the top portion and wherein the top portion may extend substantially in the vertical direction when the base portion resides on the roof. It is also preferred that the bottom opening of the boot be adapted to accept a protrusion (e.g., pipe) to be covered. In an exemplary embodiment, the top end of the top portion may have a slit, the slit running vertically down a predetermined distance of the top portion of the boot and wherein the slit allows the top opening of the top portion to be adjusted in size to fit around various sizes of pipe to be sealed.
In another exemplary embodiment of the present invention, the top portion may be used without a base in certain situations.
The boot of the present invention may preferably be formed by: providing a first piece of material having a first side edge and a second side edge; forming a top portion having a bottom opening and top opening and a slit portion at a top end of the top portion, said top portion formed by sealing a bottom portion of the first side edge to a corresponding bottom portion of the second side edge; heating and then compressing the bottom edge of the top portion so that the bottom edge turns horizontally outward forming a flat horizontal circumference around the entire bottom of the top portion; providing a base portion; and sealing a bottom edge of the top portion with the base portion so that the top portion may be substantially vertical with respect to the base portion when the base is in the flat horizontal position.
In one embodiment, the bottom edge of the top portion may be folded and positioned around the edge or perimeter of the opening in the base portion. The bottom edge of the top portion may then be welded to the base portion to form a weld that may be substantially flat on the same plane as the base portion. This weld allows the base portion to lay substantially flat during the welding process obviating the need to deform the edge of the base opening to accomplish the weld. In this embodiment, the bottom edge of the top portion may overlap the perimeter of the opening of the base portion or the perimeter of the opening of the base portion may overlap the bottom edge of the top portion when welded.
In an alternative embodiment, the edge of the base portion may be folded up to make a lapped engagement with the vertical portion of the top portion. Accordingly, a weld may be made along the substantially flat base portion as well as the vertical top portion to provide a strong seal (i.e., welded).
In yet another embodiment, the top portion may be used without a base. Particularly, when the bottom edge of the top portion is turned out with a sufficient width that a seal may be formed with the roof or roofing membrane, then a base may not be needed. In this embodiment, the bottom edge may be of such a sufficient width that it may serve as a base. Top portions may be sized at the factory to fit particular sizes of pipes on roofs, or the top portions may comprise a slit near their top for adjustments to fit different sizes of pipes.
The boot may then be installed by: placing the bottom opening of the top portion over a protrusion to be covered; placing the base portion (if it has a base portion) flat over the roof; pulling a top portion of a side edge of the vertical portion around the protrusion (e.g., pipe) so that the top opening of the top portion may be adjusted to fit the protrusion; sealing the top opening of the top portion around the protrusion; and sealing the base portion to the roof or roofing membrane. If an embodiment is used without a base, the bottom edge of the top portion that has been turned out to a sufficient width may be sealed directly to the roof or roofing membrane.
In another open boot flashing embodiment, the flashing may be open to allow the flashing or “stack” to be wrapped around the protrusion to be covered. After wrapping the protrusion, the top and base portions are welded to complete the seal. The open flashing may preferably be comprised of:                a base portion having an opening; a top portion attached to the base portion along the opening in the base portion; a break in the base portion and the top portion, the break in the base portion separating a first portion of the base portion from a second portion of the base portion, and wherein the break in the top portion separates a first portion of the top portion from a second portion of the top portion; and wherein the break allows the apparatus to be opened to accept a protrusion on the roof to be covered and wherein the first portions of the base portion and the top portion may be pulled around the protrusion and sealed to the second portions of the base portion and top portion, respectively. The first portions of the base portion and top portion may be adjustably pulled around the protrusion to accommodate protrusions of various sizes.        
In one embodiment, the bottom edge of the top portion may be folded and positioned around the edge or perimeter of the opening in the base portion. The bottom edge of the top portion may then be welded to the base portion to form a weld that may be substantially flat on the same plane as the base portion. This weld allows the base portion to lay substantially flat during the welding process obviating the need to deform the edge of the base opening to accomplish the weld. In this embodiment, the bottom edge of the top portion may overlap the perimeter of the opening of the base portion or the perimeter of the opening of the base portion may overlap the bottom edge of the top portion when welded.
In an alternative embodiment, the interior edge of the base portion may be folded vertically straight up to make a lapped engagement with the vertical wall of the top portion. Accordingly, a weld may be made along the overlapped portions to provide a strong weld.
A flat edge having sufficient width formed at the bottom of the top portion may be formed by placing the top portion into a die, with a portion of the material sticking out. A seal forming cone and handle may be inserted into the top portion. This material sticking out above the die may then be heated for a sufficient time to disrupt the molecules in the material, thereby allowing the material to expand. The handle may then be placed in its locking position, extending the members that may resemble pie sections of the seal forming cone and pushing the material outward so that a horizontally flat circumference (i.e. bottom edge with sufficient width) may be formed.
In addition to the novel features and advantages mentioned above, other objects and advantages of the present invention will become readily apparent to those skilled in the art from reading the following detailed description of the drawings and exemplary embodiments.